The invention relates generally to the field of liquid dispensing, and in particular to the dispensing of liquids into relatively small wells. More specifically, the invention provides systems and methods for rapidly filling ells of multi-well plates with precise volumes of liquids.
In various fields of chemical and biological research, there is a need to place known volumes of liquids within wells to facilitate the performance of various procedures. One common procedure is the performance of assays where various chemicals or substances are introduced into the wells and any reactions are evaluated. As another example, synthesized chemical compounds which have been cleaved from solid supports are typically transferred to sample wells for analysis. Various liquids are introduced into the wells to assist in identifying a particular compound as generally known in the art.
The wells which receive the liquids are often formed in plates in a standard arrangement or format. For example, one common format is a 96 well format where the plate is generally rectangular in geometry and has its wells arranged in eight rows and twelve columns. Such multi-well plates are well known within the art and are available from a host of commercial supplies, such as Polyfiltronics. The use of standard sized plates is advantageous because such plates may be used with most commercially available handling and processing equipment. For example, most automated plate readers, some speed vacuum concentrators, autosamplers, robotics liquid handling equipment, and the like, are configured to operate with standard multi-well plate formats.
One common way to introduce liquids into the wells of such plates is to use a multi-channel air-displacement pipette. For example, when using a 96 well plate, multi-channel pipettes with eight tips are available to simultaneously fill an entire one of the columns with the same liquid. To fill the wells, the user manually places the array of pipette tips into a liquid source to aspirate the liquid into the pipettes. The user then places the array of pipette tips into one of the columns of wells and squeezes a plunger to force an amount of liquid out of the pipettes and into the wells.
Such a process suffers from a number of drawbacks. For example, such manual transfer of the liquid is burdensome and time consuming. Further, certain fluids, such as those with high vapor pressures at room temperature, tend to be difficult to dispense with such air-displacement pipettes since the pressure in the pipette tips often forces out droplets of the fluid even before dispensing is desired. This causes both inaccuracies in dispensing and placement of fluid in unwanted locations on the plate. Such a deficiency is particularly troublesome when dispensing highly corrosive or otherwise hazardous liquids, such as trifluoroacedic acid (TFA).
Automated systems for dispensing fluids into multi-well plates are widely available. Typically, such systems are not constructed of materials that are compatible with highly corrosive materials. In addition, many of these systems are large compared with chemical vapor hoods which are typically used in chemistry laboratories and which are required when using hazardous liquids like TFA.
Hence, it would be desirable to provide improved apparatus, systems, and methods for transferring liquids into wells of multi-well plates that would overcome or greatly reduce the drawbacks associated with prior art techniques. In particular, it would be desirable to provide ways to rapidly and efficiently fill the wells with the desired liquids. Further, such systems and methods should be safe to ensure that hazardous chemicals are properly transferred and should be small enough to be placed in conventional chemical vapor hoods. Still further, the systems and methods should allow for precise volumes of liquids to be transferred into the wells.